#include <fstream>
#include <vector>

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

const int nmax=100000, nmax2=17;

vector <int> g[nmax+1];

int v[nmax2+1][2*nmax], lg[2*nmax], pv[nmax+1], l[nmax+1];

int poz=0;
void dfs(int x){
    poz++;
    v[0][poz]=x;
    pv[x]=poz;
    for(int i=0;i<int(g[x].size());i++){
        int xn=g[x][i];
        l[xn]=l[x]+1;
        dfs(xn);
        poz++;
        v[0][poz]=x;
    }
}

int main(){
    int n,m;
    fin>>n>>m;
    for(int i=2;i<=n;i++){
        int x;
        fin>>x;
        g[x].push_back(i);
    }
    l[1]=1;
    dfs(1);
    for(int i=2;i<=2*nmax-1;i++){
        lg[i]=lg[i/2]+1;
    }
    n=poz;
    for(int i=1;i<=lg[n];i++){
        for(int j=1;j<=n-(1<<i)+1;j++){
            if(l[v[i-1][j]]<l[v[i-1][j+(1<<(i-1))]]){
                v[i][j]=v[i-1][j];
            }else{
                v[i][j]=v[i-1][j+(1<<(i-1))];
            }
        }
    }
    for(int i=1;i<=m;i++){
        int x,y;
        fin>>x>>y;
        x=pv[x];
        y=pv[y];
        if(x>y){
            int aux=x;
            x=y;
            y=aux;
        }
        int log2=lg[y-x+1];
        if(l[v[log2][x]]<l[v[log2][y-(1<<log2)+1]]){
            fout<<v[log2][x]<<"\n";
        }else{
            fout<<v[log2][y-(1<<log2)+1]<<"\n";
        }
    }
    return 0;
}